Engine



R. A. COFFMAN I 1,797,328

ENGINE March 24, 1931.

Filed June 15, 1928 2 Sheets-Sheet l W 33 ,ZZM Z 0017mm awe/(Muss,

March 24, 1931. A. COFFMAN ENGINE 2 Sheets-Sheet 2 Filed June 15 1928 'jPat nt d Mai- .24 1931: r

nosoonm m Honintuit)on; ont roniirin'f? I "Application m ritime 1928;, Serial i\1io.'285,713.,

The present invention has for one-of its objects, the provision of 1 an engine "which will be light and compact, thestructurebeing adaptedfor-use primarily but not exclusive-f (If lyin an airplane." "Another'objectiofthein- I vention 'is: to provide novel'mea-ns fOI'iQCOmpressing the charges A further object of the invention'is to providenovel meansfor int g the fuelinto the engine rand for scouring out the fi aust charges. I r

; It is Within therprovmce' of the disclosure to improve generally and to "enhance the u y Ofdevics ofthat type r0 whichthe invention appertains' a J 'With the above and other-objects in view,

which will: appear as the description pro ceeds, the invention resides in thecombination and arrangem'entof parts'andfin the dc tails of construction hereinafter. described andclaimed, it being understood that changes in the, precise embodiment of the invention 1 herein-disclosed, may-bemade within the vparts as'theywill appear at the timeithe charge is compressed; 1 s

, 1 la y l n 0 I H u jFigure 3 1s a-longltudlnal section; c 'F gure 4 1s a transversesection on the line 1 4-4 of Figure 2, the line 2f2of Figure 4 indicating the cutting plane for Figure 2 Figure 5 is a section on the line 55 of Fig ure 2, the line 3-3 in Figure cutting plane for Figure 3. 7 p p The invention includes a cylinder, embodying'an outer member 1 carrying a head 2, the head and the outer member 1 being providedlwith the usual cooling fins3,"although the enginemay be cooled in any desired way.

A spark, plug mounting 4 is located in the head 2 and'is to be taken as typical of any suitable means whereby the charge may be exploded. o ,1 1

The cylinder includes an innerJmeInber 5 extended within the outer memberl, the

outer member 1 and the inner member 5 havin the outer '14 carried by the end of the piston being 5 indicating the ing cooperatingfianges 15 whichiarei seeured together, there being'a space 6 between-the outer member land the inner member 5;the

inner member 5 extending for-a considerable distance within the outer member-1, as Figure 1 clearly shows. 'The space between the inner member 5 and the outer member 1 is marked bythe' numeral 6. A sleeve piston! mountedto reciprocate member 1 and slidesin the space 6 which exists between the outerjmem'ber 1;

and the innervinemberoof the engine cyl 1nder. :The sleeve piston 7 has an end wall 8 which is inclinedyas shown iniFi'gures l and '2. The end wall-8'l1as an inwardly: extended hub 9." In the end of the piston: 7, about the hub 9 there is anannular "chamberlOQ Re- 1 inforcing' flanges 11 extend between the body i portion of the piston :7 and the hub 9, the

flanges-being 1' oined tolthe endwall 8Fof the 3 piston. The. numeral 12 marks a hollow pisto slide in a gland ton rod which is'mounted the inner member 5 of the pistons One endl6 of the hollow r'OdlQis-secured in the hub'9 of the piston- 7,

the space'between'the ends 1 6 of the rod 12 and the outersurface'oftheend 'wallT8' 'of 1 7 p v filled asuitable-closure plug 17, ofany desiredsort. The. end of the hollow rod 12 is closed by a plug '18, which may be threaded in place,

" as shown inFigure'l of the drawings;v The rod 12 has anannular flange 1 9, which abuts against the inner end ofthe hub 9, and securing devices 20 connect the flange 19 with the hub. v The securing devices QQgmay' be countersunk into the hub, asshown in Figs ure 1 of the drawings, and the'openings in the hub 9 'for the. deviciesQOihay befclose'd as shown at 21, soithat the'wall 8 ofjthe piston 7 presents a smooth" surface to the firing chamben. v 1 a, H

, The numeral 22 designates a tubular guide mounted to reciprocate inside of -the inner member 5 of the cylinder. The guide22 is provided withanoverhanging riml23v at one end. The guide. 22 has'ioppositely dis posed inwardly projectin'gbearings Qt, for the "reception of a hollow wrist pint-25 in the ends of which headed closures 26 are mounted. I r

The numeral 27 denotes an inverted U-shapedyoke, the depending arms of which are mounted to swing upon the wrist pin 25 at the inner ends of the sockets 24; The

' loweryend of the hollow piston rod 12 is -mediate portion of the yoke 27.

threaded as shown at 28, or secured otherwise, in the intermediate portion ofthe yoke 27. Oil ducts 29 extend through the inter- The guide 22 is supplied with inclined slits30, and there are openings 31 :in the guide, the openings 31 being lo; cated on the opposite side of the soekets 24' thoroughlylubricated as it reciprocates in 1 of the cylinder.

the spaceshown at 6. Therewill also be adequate lubrication for the yoke 27 where it is mounted on the wrist pin 25. The numeral 33 denotes a connecting rod provided at .its upper end withthe bushed eye 3 .mounted on a hollow wristpin between the side arms of the yoke 27. T he eye 3% of the connecting rod 33-,and the enclosed bushing 35, are provided with registering openings 36 which admit oil upon the wrist pin 25,.within thefbushing The outer member 1 of the cylinder has an intake port 37 through which the fuel is forced by any suitable means (not shown). is provided in its side wall with an intake port 38 which theintake port the cylinder. The outer member 1 of the cylinder is provided with an exhaust port 39. There is a bypass to in the outer member The piston 7 is provided in its. side wall with a port 4L1 adapted to register with the bypass 40. In the working end of the piston there is a channel 42, one end of which extends lengthwise ,of the piston, and the other end of which extends transversely of thejpiston and is adapted to communicate with the bypass 4:0. 7

Although the cylinder of the engine may stand in any desired position with respect to the vertical, it will be supposed that the cylinder is standing vertically, and the terms up and down will be used, for convenience, in describing how thepiston 7 moves.

The piston 7 moves up to the position shown in Figure 3, until the intake port 38 of the piston 7 is'in registration with the intake port 37 of the outer member 1 or the cylinder, as shown in Figures 3 and 5. The gas e'ous fuel is forced through the registering in its "side wall wall of The piston 7 is adapted to register with 37 of the outer ;member 1 of ports 37 and 38, into the space between the top of theinner member 5 of the cylinder and the end wall 8 of the piston 7. The piston 7 moves downwardly, making a power stroke under the impulse of the gas which is exploded in the head 2 of the cylinder above the piston 7. As the piston 7 moves downwardly, the gas is compressed between the end wall 8 of the cylinder and the upper end of the inner member 5 of the cylinder until the piston has arrived in the position shown in Figure 2 of the drawings. As the piston 7 moves to the position shown in Fig ure 2 of the drawings, the port 11 in the side the pistonv comes into registration with the lower part of the bypass 40 in the outer member 1 of the cylinder and the compressed'gas-in the annular chainberlO flows through the port ll into the bypass i0,

The, compressed gas moves upwardly from the bypass 10 through the passage 42 in the piston 7 and is projected upwardly with great fo'rce into the upper part of the cylinder,the Y exhaust being forced downwardly and: laterally and outwardly through the exhaust port l 39, the exhaust port being' openat, this time because the end wall 8 of the piston is in the position shown in Figure 2. The lateral inclination of the end wall 8 aids in the expel ling of the exhaust through the port 39. The

upper end of the cylinder now is full of fresh fuel and as the piston 7 moves upwardly, the charge is compressed between the end wall 8 of the piston andthe head 2, the charge being exploded by any suitable means mounted in the opening i of Figure 1.

- .As the piston 7 reciprocates, the rod 12 slides in the gland 14 and motion is imparted to the guide 22, the guide reciprocating in the inner member 5 of the cylinder, below the upper end of the inner member 5, motion beingtransmitted to the connecting rod 33 by way of the wrist pin 25. V p

'The inner 'end of the member 5 of the cylinder prevents theoil from coming into contact with the inner surface of the end wall 8 of thepiston 7 and frying out thereon, to the detrimentof the oil. Althbugh the end wall 8 of the piston 7 is not cooled by contact with the oil, the flanges 11 will serve to cool the end ofthe piston. When the piston moves to the position shown in Figure 2, the

compressed charge within the chamber 10 flows out from among theflanges 11, and the flanges, in this way, act as cooling vanes.

Attention is directed at this place to the overhanging rim '23 at the inner end of the guide 22; llo matter. how the cylinder may stand with respect to the vertical, the rim 23 serves to receive and turn back toward the opposite end of the guide, oil that may find its way intothe guide.

Having thus described the invention, what is claimed is v n 1. An engine comprising a cylinder including'an inner member and an outer memb'e'm cupshaped sleevepiston mounted to'slide between the inner and outer 'members of the I vcylinder, a guide-slidable in the inner member. of the cylinder, aiconnecting rod as-' sembled with -the guide a 'rod slidable in the endotthe innermemb'er ofthe cylinder and connected to the pistonand to the guide,

"means for admitting a charge within the piston ior compression and means for transferring the charge from' thepiston to the outer member or the cylinder to effect an expulsion-of the exhaust, the piston being in close, slidable contact with'the inner and outer members of the cylinder, thereby to confine the compression between the end of the inner member of the cylinder and-the end of the piston, 2. An engin e comprising a cylinder including an inner member and an outer member, a cup shaped sleeve piston mounted to slide.

between the inner and outer members of the cylinder, means for admlttinga charge nto the piston for compression, means for transferring the compressed chargev from the,

piston to the outer member of the cylinder to efiect janexpulsion of the exhaust, the piston being in close, slidable contact with the inner and outer members ofthe cylinder, thereby to confine'the compression between the end of the inner member of the cylinder and the end of the pistom-the guide having perforations which admit oil on the inner surface of the inner member of the cylinder whilst the guide is sliding thereon, the inner her, a cup shaped sleeve piston mounted to slide between the inner and outer members of the cylindergan annular guide slidable in the inner member of the cylinder andjprovided at its inner end with an overhanging oil-deflecting rim, a connecting rod assembled with the guide, a rod slidable in the inner member of the cylinder and connected to the piston and toqthe guide, means forfadmitting a charge within the piston for compression, and means for transferring the charge from I the piston to the outer member of the cylinder to effect an expulsion of the exhaust. i

4. An engine comprising a cylinder including an inner member and an outer member, a cup shaped sleeve piston mounted to, slide between the inner and outer members of the cylinder, thepiston having an end wall, and the inner member of the cylinder having an piston, the wall of the piston having in-- expulsionofthejexhaust,'

ternal cooling'fins, arod. slidable in the inner membejr of the Icylinderand connected to the piston, means for admitting a charge within:

theipiston forcompression, andJmeans for transferring the charge fromfthe piston to i the outer member of the cylinder to efi'ec'tan for 5. An engine comprising a cylinder having opposed heads, thewalls of the cylinder beingprovided with an exhaustport, aninlet port, and with a passage affording a Joy-pass connection adjacent one end'of the cylinder, and a sleeve piston 'reciprocable in thezcylin- 'der and havingitsfsleeve portion slidable on and surrounding one of said heads, said sleeve portion being provided with an inlet" port adaptedto register withthe inlet port of the cylinder, and a discharge port adapted 1 to register with the passage of the cylinder. 6. Inapparatus of the .class described, a

cylinder, a head forsaid cylinderi having a gland extending outwardly, a piston infthe cylinder, a piston rod extending through the gland, and a cylindricalbearingshoe secured to tlie piston rod beyond the gland, aportion' of the, shoe overlying the gland when the piston isat its innermost position;

7. in apparatus ofthe. classidescribed, a

cylinder, a cylindrical bearing extension car ried by the cylinder, sleeve-bearing slidablein the bearing extension, a piston, rod secured to the sleeve bearin'g, and apistoni,

connected to-the'piston rod reciprocablein the cylinder, the sleeve bearing being slotted to aflord lubrication slots extendingiat an angle to the direction of movement of'the;

sleeve bearing. 7

8. An engine comprising spaced inner and.

outer cylinders, a sleeve slidable in between the cylinders, and a lubricating member 'reciprocable within theinnercylinder, the

inner cylinder having perforations cooperat ing with slots the lubricating member.

- 9. An engine comprising spaced inner and vouter cylinders, a sleeve piston reciprocable inthe outer'cylmder and, having its sleeve portion slidable in the space between the cylinders, a piston-rod having a bearingmeinber engagingthe inner walls of the-inner piston, the inner cylinder: having openings cooperating with lubricating slots in said bearing member. I

In testimonythatl claim the foregoing as my own, I have hereto affixed my signature.

, ROSGOE A, COFFMAN.

end wall'wh-ich prevents oil within the inner member from reaching the end wall oi the 

